The present application relates to providing thermal management for battery modules that need to be cooled or heated.
Hybrid and electric vehicles provide an alternative to conventional means of vehicular motive power by either supplementing (in the case of hybrids) or completely replacing (in the case of electric vehicles) the internal combustion engine (ICE). In such hybrid or electric vehicle configurations, at least a portion of the motive power is provided by one or more battery packs that act as a direct current (DC) voltage source to a motor, generator, or transmission that in turn can be used to provide the energy needed to rotate one or more of the vehicle's wheels. One valuable feature of a battery pack configuration for vehicle propulsion is that they are rechargeable, such as through a conventional 120/240 volt alternating current (AC) electric outlet. Such battery pack configurations are known as Rechargeable Energy Storage Systems (RESS), which may be configured as one or more modules made up of a series of individual batteries.
RESS assemblies require thermal management in order to maintain performance and integrity. Under certain circumstances, charging or operation of batteries of the RESS at too high of a temperature can decrease the life of the batteries. Similarly, under certain circumstances, charging or operation of batteries at too low of a temperature can cause permanent battery damage. Therefore, in order to overcome the possibility of such events and to promote increased battery efficiency, conventional thermal management systems have been developed.
In one conventional configuration of a thermal management system, the RESS is positioned in a frame that may additionally include cooling fins, paths or channels for cooling liquid for the various cells of the battery pack. In such design, a cold plate is made from an extruded aluminum structure that is subsequently cut and machined together with a header assembly to provide cooling path turns that are machined or otherwise formed within the plate. Such design of the cold plate requires multiple pieces and tight tolerances during manufacture to (among other things) maintain plate flatness.
As one example of the thermal management approach of a conventional RESS thermal management system, reference is made to FIG. 1. The approach is configured as an assembly of multiple plates (for example, a front plate 10 and a rear plate 15) thermally connected to one another by a coolant conduit 55 that forms a cooling path. The front cooling plate 10 is made of upper and lower plate sections 20, 25, and the rear cooling plate 15 is made of upper and lower plate sections 30, 35. Between the upper and lower plate sections 20, 25 of the front cooling plate 10 are a series of channels 40 through which the coolant flows. Such channels 40 are machined, molded, or otherwise formed between the upper and lower plate sections 20, 25. Channels may also be formed by installation of a separate flowpath device into a cavity otherwise existing between the upper and lower plate sections 20, 25. Similarly, there are coolant channels 45 between the upper and lower plate sections 30, 35 of the rear cooling plate 15. A coolant inlet pipe 50 is connected to the coolant channels 45 of the rear cooling plate 15. Coolant flows through the inlet pipe 50 and through the coolant channels 45 in the rear cooling plate 15. Conduit 55 connects the coolant channels 45 of the rear plate 15 with the coolant channels 40 of the front cooling plate 10. Coolant flows from the conduit 55 and through the coolant channels 40 of the front plate 10 and then exits through coolant outlet 60.
Although conventional approaches to thermally managing a RESS assembly, such as those set forth above, do exist, there are nevertheless ongoing limitations to conventional methods and devices.